The central dogma of molecular biology describes the way genetic information is expected to be transferred in a single direction through a biological system. It was first stated by Francis Crick in 1958 and re-stated in a Nature paper published in 1970
Information flow in biological systems:
The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or nucleic acid.
Or, as Marshall Nirenberg said, "DNA makes RNA makes protein." (does not go the other way)
To appreciate the significance of the concept, note that Crick had misapplied the term "dogma" in ignorance. In evolutionary or molecular biological theory, either then or subsequently, Crick's proposal had nothing to do with the correct meaning of "dogma". He subsequently documented this error in his autobiography.